Electromagnetic high-current-carrying-capacity vacuum relay



Awg-v '0 1965 J. s. HAWKINS 3,200,222

ELECTROMAGNETIC HIGH-CURRENT-CARRYING-CAPACITY VACUUM RELAY Filed Oct. 15, 1962 3 Sheets-Sheet 1 INVENTOR. JACK S. HAWKINS AGENT 0, 1965 J. s. HAWKINS 3,200,222

ELECTROMAGNETIC HIGHGURRENT*CARRYING-CAPACITY VACUUM RELAY Filed Oct. 15, 1962 3 Sheets-Sheet 2 INVENTOR. JACK S. HAWKINS AGENT g- 10, 1965 J. s. HAWKINS 3,200,222

ELECTROMAGNETIC HIGH-CURRENT-GARRYING- CAPACITY VACUUM RELAY Filed Oct. 15, 1962 3 Sheets-Sheet 3 HVVQHVTZHL JACK S.HAWKINS AGENT United States Patent 3,209,222 ELECTROMAGNETIC HIGH CURRENT CARRY- ING-CAPACETY VACUUM RELAY Jack S. Hawkins, San Jose, Calif, assignor to Jennings Radio Manufacturing Corporation, San Jose, Calif., a

corporation of Delaware Filed Oct. 15, 1962, Ser. No. 230,343 11 Claims. (Cl. 200-144) This invention relates to transfer relays, and particularly to an electromagnetically operated multiple contact relay of the parallel leaf spring type.

High current electromagnetically operated transfer relays have in the past been plagued by the inability to withstand impact shock and vibration characteristics imposed by contemporary environments such as jet planes and missiles. It is therefore one of the principal objects of the present invention to provide a high current carrying transfer relay having a multiple contact configuration capable of withstanding vibration up to about GS at about one thousand cycles per second.

Reliability of a relay has been another quality demanded by military applications in which failure of a relay because of its inability to carry high electric currents could be disastrous. It is therefore another object of the present invention to provide a transfer relay designed to carry continuously at least 200 amps of direct current without harmful effects due to the generation of heat by the passage of such large amounts of current.

Another factor important in determining whether a transfer relay possesses the requisite reliability for use in systems which do not permit of failure is the necessity of various difficult to achieve adjustments to provide proper gap spacing and voltage standoff between contacts during operation, and the necessity of additional adjustments required to be made after the unit is assembled so as to maintain the relay in operation. Accordingly, it is a still further object of the present invention to provide a transfer relay in which all adjustments are made during fabrication and in which no adjustments are necessary after the unit is sealed.

Although reliability of the unit is an extremely important factor in determining Whether a relay is suitable in a particular environment, another important factor is the cost of the unit. Cost is often determined by the complexity of the design and a requirement for skilled labor in fabricating the parts and assembling the unit. It is therefore a still further object of the present invention to provide an electromagnetically operated high current carrying transfer relay in which the individual parts can be mass produced and assembled by relatively unskilled labor, thus reducing the initial cost of the relay.

It has been found that one way in which high current carrying capabilities is achieved is to separate the phases in a three-phase cicuit and interrupt each phase separately. It is accordingly another object of the invention to provide a three-phase high current carrying transfer relay.

At the high currents .at Which the relay of this invention is designed to operate, one of the problems required to be solved is the isolation of each phase from the other phases in the three-phase relay. It is therefore another object of the invention to provide adequate phase shielding between the three phases of the relay.

A still further object of the invention is the provision of a transfer relay in which different configurations such as single-pole single-throw, or single-pole double-throw, or three-pole single-throw may be arranged simply and effectively using many of the same parts common to all configurations and utilizing the same methods of assembly.

Still another object of the invention is the provision of a novel method of assembling a transfer relay so that the contact parts after assembly and final seal are in finally adjusted position and require no further adjustment after the unit is sealed.

Still another object of the invention is the provision of a hermetically sealed envelope for a high current carrying transfer relay in which shield means are provided to prevent formation of a conductive coating of vaporized contact metal on the inner non-conducting surfaces of the envelope.

The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the showing made by the said description and the drawings, as it may be incorporated in various forms Within the scope of the appended claims.

Broadly considered, the transfer relay of the invention comprises a generally cylindrical hermetically sealed envelope fabricated from a multiplicity of stacked and alternately arranged dielectric and metal parts hermetically brazed one to the other, and having appropriately interposed therealong a multiplicity of radially extending terminal plates or contact flanges of heavy ores-section and having a portion projecting outside the envelope as thermal radiating elements, and a portion extending into the envelope to provide a solid and vibration-free support for the current carrying contact assembly. Each of the an- 1 nular contact flanges supports adjacent its inner periphery a heavy tungsten contact extending in a direction parallel to the axis of the envelope and having an appropriate contacting surface adapted to be engaged by a movable or floating contact plate suitably supported on the envelope and actuated by a central actuating stem. Each of the movable contacts includes a metallic ring, preferably of molybdenum, having a radially extending resilient finger extending past the central axis of the envelope and having brazed on the free end thereof a heavy floating contact plate or shorting bar adapted to short circuit spaced and fixed contact points wihtin the envelope. The actuating stem is supported on a floating armature adapted to be energized by a suitable solenoid assembly hermetically closing one end of the envelope. In one aspect of the invention the relay is adapted to separately interrupt the phases of a three-phase circuit so as to prevent interference between the phases when a circuit is broken therethrough. Each phase is provided with a pair of contacts isolated within .a separate contact chamber from adjacent contacts. In another aspect of the invention the relay comprises a single-pole double-throw relay utilizing a common contact flange isolating the two switches.

Referring to the drawings:

FIG. 1 is a vertical cross-sectional view of a threephase relay, the plane of section being indicated by the line 11 in FIG. 4.

FIG. 2 is a vertical cross-sectional view taken in the plane indicated by the line 22 in FIG. 4.

FIG. 3 is a horizontal cross sectional view taken in the plane indicated by the line 3-3 in FIG. 1.

FIG. 4 is a plan view of the embodiment illustrated in FIG. 1.

FIG. 5 is a vertical cross-sectional view of a different embodiment of the invention in a single-pole doublethrow relay.

FIG. 6 is a fragmentary cross-sectional view taken through a portion of the wall as indicated by the line 66 in FIG. 5.

FIGS. 1, 2 5 are shown twice actual size, FIGS. 3 and 4 are shown actual size, and FIG. 6 is shown four times actual size for clarit In terms of greater detail, the transfer relay in the embodiment disclosed in FIGS. 1, 2, 3 and 4 comprises an hermetically sealed generally cylindrical envelope porend bya solenoid assembly 3 and at the other end closed 7 by a domed end cap assembly The electromagnetic solenoid assembly comprises a generally tubularhous'ing portion 5 having a coaxially arranged core member 6 therein supported on the housing 5 by an integral and transversely extending errnetic wall '7. The wall is "spaced intermediate opposite ends of the housing, the inner end portion 8 of the housing being provided with aradially' extending seal flange 9. The other end of the housing is provided with a detachable closure plate 12 secured to the open end of the housing by a suitable screw or bolt 13, the closure plate serving to enclose a magnetic coil 14 within the housing and complete the magnetic circuit around this end of the housing. A radially extending flange i6 is provided brazed about the outer periphery of the housing to serve as a mounting means for the relay. An armature 17 is provided adjacent the inner end 8 of the housing and is adapted to move axially toward and away from the. housing upon energization and de-energization of the solenoid. Suitable spring means 18 are interposed between the wall 7 and the armature.

ln FlGS. 1, 2, and 5, the armature is shown in coreenergized position. Inasmuch as similar electromagnetic solenoid means are utilized for the separate embodiments illustrated in H65. 1 and 5, corresponding parts have been indicated by corresponding reference numbers. In

- equalize stresses on opposite surfaces of the flanges.

both embodiments axial, movement of the armature is restricted in one direction by the inner end 8 of the housing, and in the other direction by a radially extending flange 19 formed on one end of a cylindrical metallic shell portion 21, the other end of which is provided with an integral and radially outwardly extending flange portion 22 abutting against and having its outer peripheral edge coincident with the outer peripheral edge of sealing flange 9. 1 The coincident edges of flanges 22 and 9 are adapted shell member 2 1 and hermetic wall 7 are fabricated from non-magnetic material.

, The armature 17 is of course fabricated from a magnetic material of a thickness and diameter suitable to form a low reluctance path across the inner end of the housing.

Fixedly secured centrally in the armature 17 is an axially extending metallic support rod 23, serving to support a multiplicity of axially aligned dielectric segments 24, 26, 27, 28, 29, 31, and 32. The dielectric segments are preferably short tubular ceramic segments'stacked one above the other in abutting relation as shown and secured in place by a suitable nut 33 engaging the threaded free end of rod 23. Selected ones of the di-' electric segments are provided with reduced diameter portions seated within cornnlementarily recessed portions in adjacent dielectric portions. i

All

Each of the dielectric rings 36 is appropriately metalized on each of its transverse surfaces, which surfaces are hermetically united as by brazing to an associated metallic ring member 3&each metallic ring member being provided with a radially inwardly extending flange portion 39. Selected ones of the ring members 33 are additionally provided with a cylindrically extending flange 4th intergal with the inner periphery of the radially extending flange 39. the radially inwardly extending flanges 39 are hermetically brazed to the adjacent ceramic rings. Where desirable or necessary, suitable dielectric backing members 41 are brazed to the opposite surface of radially inwardly extending flanges 39 from the ring 36 to As shown in the drawing, where the cylindrically extending flange ill is provided on the ring members 3%, the flange is spaced radially inwardly an amount suflicient to provide clearance between the re-entrant flange 37 on ceramic memberdd and the cylindrical flange 40.

This construction is shown in enlarged cross-section in FIG. 6. 7

To hermetically unite each sub-assembly comprised of one ceramic ring 36 and two adjacent metallic rings 38 with adjacent envelope sub-assemblies, corresponding portions of ring members 38 extending towardeach other and are hermetically brazed to heavy metallic annular plates &2, 43, 4-4, as, 47, and 48, numbered consecutively form top to bottom as shown in FIGS. 1 and 2. In FIG. 5, since there are only three such heavy annular plates utilized, these plates are numbered consecutively 4'12, 43, and 44. Each of the heavy contact flanges or plates is provided with a radially outwardly extending portion as shown in the drawings, and with a radially inwardly extending portion'terminating at a central aperture 51 in each of the plates;

In the embodiment of the relay illustrated in FIGS. 1

and 2, plates 43 through 48 are provided with a centrally disposed coaxial metal shield cylinder 52 pressfitted and brazed within the central aperture 51. Each of the shield cylinders 52 closely surrounds the central actuating stem'23. V

In the embodiment of the relay illustrated in FIGS. 1, 2 and 5 each of the plates 42, 44 and 47, support a heavy cylindrical contact member 53 having a'longitudinal axis extending parrallel to the axis of the envelope and provided intermediate its ends with a groove in the nature of a transversely extending her-f providing a con- As clearly shown in FIGS. 1, 2 and 5, the armature and its attached, centrally disposed rod 23 are coaxially arrangedrwith respect to the envelope assembly '2, the rod or actuating stem extending substantially from one end of'the envelope assemblyto the other. The alternate dielectric and metallic envelope assembly 2 is prc- 'ferably fabricated from ceramic ring members 36 axially aligned and spaced one from the other, each being provided on its inner periphery with a re-entrant cylindrical flange portion 37 radially spaced inwardly from the inner periphery of the ring. The re-entrant flange portions on the crearnic rings serve to prevent the formation of a continuous conductive patch between ad acent metallic I portions of the envelope.

tact surface 54 and an abutment surface or stop 55. Each contact member is brazed in a suitable aperture formed in the associated contact flange at a point spaced from the central axis of the envelope. As shown best in FIG. 3, the remaining portion of contact 53 forming" the bottom of the groove provides a vertical abutment or surface 57 for purposes which will hereafter be explained.

.Comparingthe relationship of contact members 53 in FIGS. 1 and 5, it will be seen that in FlG.'1 the contact members 53 all extend in the same direction, whereas in FIG. 5 the contact; members extend in opposite directions. Thus, in FIG. 5, the groove in contact 53 in the uppermost contact illustrated is adjacent the lower end of the contact, whereas in the lowermost contact 53 illustrated in FIG. 5 the groove is adjacent the upper end of the contact. In FIG. 1 the'grooves in con tact members 53am oriented adjacent the lower end of the contact member as shown;

On each of plates 43,46 and 4% in FlGS. 1 and 2, and on plate 43 in FIG. 5, a contact member 53 is provided brazed in a suitable aperture formed in the associatedcontact flange, and providing a contact surface 5% lying in a plane coincident with the contact surface 54 on contact member 53. Each of the contact members 58 is cylindrical about a longitudinal axis parallel to the axis of the adjacent contact mcrnberfi?) and the central axis of the envelope.

flange 43 is provided with a pair of such contact members 58, each extending on opposite sides of plate 43 so that corresponding surfaces 59 lie in parallel axially spaced planes also containing contact surfaces 54 of associated contact members 53. In this embodiment the plate 43 and its associated contact members 53 provide a common conductive path associated with each of the contact members 53 lying on opposite sides of plate 43.

In order to complete an electrical circuit between the contact members 53 and 58, a mobile contact assembly is provided comprising an annular metallic member 61 sandwiched between one of the metallic envelope ring members 38 and a ceramic backing member 41, and provided with a radially inwardly extending resilient finger portion 62 having a heavy contact member 63 of thick crosssection brazed on the free end of the finger 62. A suitable baflle 64 is provided mounted adjacent the free end of the finger 62 in close proximity to the associated shield cylinder 52. The baffle plate 64 and shield cylinder 52 cooperate to prevent vaporized contact material from migrating between the contact chambers associated with the separate pairs of cooperating contact members 53 and 58. This cooperative relationship is adapted to further isolate the contact chambers from each other. This construction insures that there will be no interference between each phase of a three phase circuit.

In the embodiment illustrated in FIG. 5, it will be noted that the baffle plate 64 is omitted. The contact flange 43 in this embodiment functions to isolate separate pairs of contact members 53 and 58 from each other. Additionally, this embodiment is not a three-phase relay and separation of the phases is therefore not critical. Both of the embodiments however utilize members of relatively large cross-section suitable for interrupting and carrying large currents in the order of about 200 amps. The heavy parts also function to draw heat from the contact assembly, thus enabling a much higher current to be carried continuously without generation of excessive heat.

In order to effect actuation of the relay, each of the movable and resilient contact fingers 62 is provided with an aperture through which a reduced diameter portion of the associated dielectric stem segment projects. Adjacent segments thus trap the finger therebetween. It will thus be seen that movement of the armature by means of energization and de-energization of the solenoid will displace the resilient arm and the floating contact thereon. The parts are preferably proportioned to provide a resilient bow in the arm 62 in both of its positions. Such a resilient bow imposes a direct resilient closing force on the contacts, thus preventing or diminishing bounce due to impact shock or vibration. It will also be seen that the dielectric portion of the stem associated with each ofthe resilient contact arms 62 functions to electrically insulate the contacts from the longitudinally extending rod 23 which, like the magnetic assembly, is at ground potential.

The end of the envelope assembly opposite the magnetic solenoid assembly is closed by the end cap assembly 4v as previously indicated, the end cap 4 being provided with a cylindrically extending seal flange 66 hermetically heliarc Welded to the associated flange 38. The central portion of the end cap assembly is provided with a dome 67 and a suitable tubulation 68 protected by a cap 69.

In order that the contact surfaces 54 and 59 may be properly aligned for mating with the floating contact 63, assembly of the relay proceeds in what is believed to be a novel method. As will be seen from the following description, adjustment of the cooperating contact surfaces is automatically effected during the final braze operation.

It has been found that an economical andeffective method to accomplish this result is to pro-fabricate or pro-assemble separate sub-assemblies of the relay and braze the sub-assemblies in an initial braze operation, and subsequently hermetically join the composite sub-assemblies in a final braze operation. In this manner separate sub-assemblies may be fabricated and leak-checked before initial braze operation are conducted as follows.

6 assembly into a completed unit. One of the first subassemblies to be assembled and brazed is the solenoid assembly 3, including housing 5, flange 16, wall 7, flange 9 and core 6. These elements are assembled with suitable jigs and braze rings and passed through a brazing furnace so as to hermetically unite the members one to the other to form a composite rigid and vibration free sub-assembly.

Another sub-assembly that is initially assembled and brazed is the end cap assembly 4, with a portion of protective cap 69 thereon, and tubulation 68 in open condition. The separate parts making up this sub-assembly are suitably brazed in a single operation. It will of course be understood that appropriate brazing jigs are utilized to maintain the parts in proper alignment.

A third sub-assembly that is pre-fabricated or preassembled and initially brazed is the annular plate or contact ring 61 having the integral radially extending finger 62 thereon, floating contact 63, and baffle plate 64 brazed thereon. The contact ring 61 is conveniently stamped from .010" molybdenum sheet while the contact member 63 is fabricated from a thick piece of tungsten. Baflle plate 64 may conveniently be fabricated from .005" molybdenum.

The separate sub-assemblies are assembled and the Referring to FIG. 1, metallic envelope ring 21 is placed on a suitable jig having a center guide or alignment post of tungsten upon which are appropriately stacked in proper sequence the separate ceramic spacer members 24 through 32, respectively. Stacked on the radially inwardly extending flange 19 of the ring 21 is a ceramic ring 36, appropriately metalized. A braze ring (not shown) is interposed between the rings 21 and 36. Superposed on ring 36 is metallic envelope ring 33 having radially inwardly extending flange 39 adapted to be brazed to the adjacent metalized surface of ceramic ring 36. Seated within ring 38 on flange 39 is a backing member 41, preferably of ceramic, also brazed to flange 39. Suitable braze rings are interposed between these members so that when the sub-assembly is passed through the brazing furnace the parts will be hermetically united. It will of course be understood that appropriate jigs surround these parts during the stacking operation to maintain them in axial alignment.

The heavy copper contact flange 48 is next stacked on the ring 38 so as to cause seating of the member 38 in an appropriate groove machined in the contact flange 48. At this point it should be understood that all the subassemblies are brazed at one time and that the flange 48 is not brazed to the member 38 upon which it rests in this initial braze operation. The plate or flange 48 merely rests on the cylindrical member 38, the groove in the flange 48 acting as a guide to coaxially align the contact flange with the remaining elements of the combination. On the other hand, each of the contact flanges is brazed in this initial brazing operation to the envelope ring 38 next above the contact flange. With the contact flange in place, a suitable jig is dropped into the aperture occupied by the contact member 59 in FIG. 1 to provide an abutment against which finger 62 may abut for proper alignment when this element of the combination is stacked. The assembly of the relay proceeds by sequential stacking of elements 41, 38 and 36 between contact flanges 48 and 47, and thereabove between succeeding pairs of contact flanges 47-46; 46-44; 44-43; 43-42; and

contact flange 42 and envelope ring 38 next adjacent end cap assembly 4.

As the stacking progress, appropriate jigs are inserted in the apertures in the contact flanges in place of the contact members 58 and 53 which will ultimately be brazed in these apertures and which are shown in FIG. 1. Placement of these jigs is for purpose of ensuring proper positioning of the contacts with the resilient contact finger 62 upon final braze. From the foregoing it will be apparent that each contact flange 42 through 48 forms the .base for the next-above assembly of metallic and ceramic rings, including backing rings 41, and each of these subassemblies from the furnace, each of the sub-assemblies in the stack will be united in a composite rigid unit, but the units will not be brazed to each other. At this point this composite sub-assembly may be leak-checked to make a sure that the unit is vacuum tight. Sub-assemblies that ,are not vacuum tight-are discarded and replaced by tight sub-assemblies.

After the separate sub-assemblies are brazed into composite units, the sub assemblies are hermetically brazed to each other in the following manner. Whereas stacking of the parts comprising each sub-assembly as explained thus far proceeded from the end of the relay next adjacent the solenoid assembly toward the end-cap assembly 4, stacking of the unitized sub-assemblies is accomplished in reverse order by inverting the composite sub-assemblies and stacking them one upon the other commencing with the sub-assembly including contact flange 42. As before, an appropriate jig having a center guide pin or post is provided upon which the sub-assemblies are stacked for final brazing.

In this operation one sub-assembly acts as a jig for the next superposed sub-assembly. After the first or lowermost composite sub-assembly is stacked on the jig in inverted position so that contact flange 42 forms the uppermost element, contact member 53 is dropped into the aperture in the contact flange adapted to receive it.

The contact member is temporarily supported on the contact flange by placing a split spring ring of brazing Wire about the contact member. Placement of the split spring ring of brazing wire is gauged so that the grooved end of the contact member extends above the contact flange an appropriate distance.

At this point, ceramic stem segment 32 is dropped over the center post or guide pin so that its reduced diameter end portion extends upwardly. The second composite sub-assembly including contact flange 43 is now stacked on the first sub-assembly so that an end portion of cylindrical ring member 33 indexes in the groove formed in contact plate 42. This ensures coaxial alignment of the two sub-assemblies. It should be noted however-that the second sub-assembly includes resilient contact arm 62, the free end of which must lie Within the groove formed in contact member 53. This requires that the two sub-assemblies be brought into axial alignment while the resilient contact arm is laterally offset from the contact member 53. This places floating contact plate 63 at the proper height so that subsequent rotation of the second sub-assembly swings the floating contact into the groove in contact member 53. Rotation continues until the'fioating contact abuts the stop 57, whereupon it is turned in the opposite direction a small amount to provide operating clearance between the edge of floating contact 63 and stop surface 57.

that upon actuationof the relay to either a make or break position, the floating'contact will be resiliently pressed against at least one abutment. Such resilient pressure is provided by gauging the travel of the solenoid and there- .fore the stem so that overtravel is provided in either direction, thus producing a bow in the resilient arm 62 when the actuating stem is at either extremity of its travel. It

' has been found that in a relay having the proportions of the relay illustrated a .620" overtravel will how the re- .silient arm 62 enough to cause resilient impingement of the floating contactwith suflicient force to withstand vi- 7 bration to 10 GS at 1000 cycles per second.

' of the two braze operations each set of contact members is properly oriented with the associated floating contact.

With the second'sub-assembly in position as just de- 7 scribed, a contact member 53 is dropped through the aperture in contact flange 43 adapted to receive it. The contact member 58 will pass downwardly until its contact surface 59 rests on the floating contact 63. A split spring brazing ring is placed about the contact member 58 so that before the final braze operation it lies closely adjacent the upper surface of contact flange 43 when in inverted position.

.As the stacking of the sub-assemblies progresses, the

actuating stem ceramic sections are also stacked about the centerguide pin of the jig so as to appropriately engage the radially extending contact arm 62. The lengths T of the ceramic sections 24 through 32 making up the actuating stem are proportioned so that upon final assembly and brazing, the relationship of each floating contact 63 with the associated contact members 53 and 58 is such After the sub-assemblies are all stacked and the resilient contact arms properly oriented horizontally by appropriate rotation of each sub-assembly, the floating contacts are oriented vertically without regard to contact surfaces wand 59 by placingthe stacked ceramic sections 24 through 32 under compression so that the vertical height of each floating contact above the jig is fixed. It should be understood that at this stage of the assembly contact surfaces 5% and 59 on contact members 53 and '58 have not been oriented in a fixed relationship with respect to the floating contact 63. It will be remembered that both these contact members are temporarily supi ported on the associated contact flange by the split spring rings of brazing material.

The loosely stacked sub-assemblies are now ready for final braze, which proceeds with the, parts held in inverted position. Suitable braze material associated with each envelope .ringfifl which loosely abuts an adjacent contact flange, upon melting; hermetically unites the sub-assemblies into a composite envelope portion 2. In the same braze operation the split spring brazing rings supporting cont-act members 53 and 58 are melted, and upon melting release the contact members, which sink downwardly until contact surfaces 54 and 59 rest on the floating contact. The braze material flows by capillary action between the contact members and the associated contact flange to braze each contact member rigidly in position. .The contact surfaces 54 and 59 are now properly oriented with respect to each other and with respect to the mobile or floating contact.

It will of course be apparent from the foregoing that the sequence of assemblyof the parts, and the sequence of brazing operations may be varied to accord with different configurations. Thus, in the embodiment illustrated in FIG. 5, the lowermost contact'members 53 and .58 are vertically oriented and brazed in one operation with the relay in an upright position as shown. Then the uppermost contact members are vertically oriented and brazed with the assembly inverted. Upon completion It has been found that this method of assembly materially increases the reliability of the relay in that substantially perfect orientation of the mating contact surfaces is obtained. This contributes to simultaneous make or break as between a plurality of separate contact elements as in the two embodiments disclosed.

I claim:

.1. A relay comprising an envelope including a tubular intermediate envelope portion arranged. about a longitudinal axis and end walls closing opposite ends of the tubular intermediate envelope portion to define therewith an hermetically sealed main chamber, a plurality of axially spaced electrically conductive annular contact flanges arranged on the intermediate envelope portion to divide the main chamber into a plurality of auxiliary contact chambers, a contact assembly including fixed and mobile contact members insulatingly supported on the envelope and enclosed within each auxiliary contact chamber, each mobile contact member movable to make or break an electric circuit through adjacent contact flanges, and actu- Iating meansincluding a stem axially disposed within said main chamber and operatively connected to said mobile contacts and movable to make or break a circuit through adjacent contact flanges.

2. The relay according to claim 1, in which the contact flanges are annular and extend radially outwardly from the envelope to provide annular thermal radiating portions.

3. The relay according to claim 1, in which the contact flanges .are annular and extend radially inwardly to define the transverse walls of the auxiliary contact chambers and provide support for the fixed contact members.

4. The relay according to claim 1, in which a fixed contact member is conductively supported on each contact flange and a mobile contact member is arranged to make or break a circuit between the fixed contact members supported on adjacent contact flanges.

5. The relay according to claim 1, in which the intcr mediate envelope portion comprises a multiplicity of axially aligned alternately arranged ceramic and metal rings, selected ones of said ceramic and metallic rings having cylindrical re-ent-rant flange portions spaced radially inwardly -from the inner peripheral surface of the main chamber.

6. The relay according to claim 5, in which said ceramic and metallic rings having cylindrical re-entrant flange portions are arranged so that the cylindrical re-entrant flange portion of one ring surrounds the cylindrical reentrant flange portion of the other ring in radially spaced relation to provide an electrically discontinuous envelope wall surface between the contact flanges defining adjacent auxiliary contact chambers.

7. The relay according to claim 1, in which a pair of auxiliary contact chambers are provided and one of said contact flanges constitutes a transverse wall common to both said contact chambers.

8. The relay according to claim 1, in which shield means are provided on selected contact flanges cooperating with baflle means on selected fixed contact members to prevent migration of vaporized contact material between adjacent contact chambers.

9. A relay comprising an envelope including a tubular intermediate envelope portion arranged about a longitudinal axis and end walls closing opposite ends of the tubular intermediate envelope portion to define therewith an hermetically sealed main chamber, a plurality of axially spaced electrically conductive annular contact flanges arranged on the intermediate envelope to divide the main chamber into at least three auxiliary contact chambers with a pair of spaced contact flanges defining opposite transverse walls of each auxiliary contact chamber, adjacent auxiliary contact chambers being spaced apart .and isolated by a remaining portion of the main chamber, a contact assembly including fixed and mobile contact members insulatingly supported on the envelope and enclosed within each auxiliary contact chamber, each mobile contact member movable to make or break an electric circuit through adjacent contact flanges, and actuating means including a stem axially disposed within said main chamber and operatively connected to said mobile contacts and movable to make or break a circuit through adjacent contact flanges.

10. A relay comprising an envelope including a tubular intermediate envelope portion arranged about a longitudinal axis and end walls closing opposite ends of the tubular intermediate envelope portion to define therewith an hermetically sealed main chamber, a plurality of axially spaced electrically conductive annular con-tact flanges arranged on the intermediate envelope portion to divide the main chamber into a plurality of auxiliary contact chambers, a contact assembly including fixed and mobile contact members Within each auxiliary contact chamber, one or" said fixed contact members being conductively supported on each contact flange and each said mobile contact member arranged to make or break a circuit between the fixed contact member's supported on adjacent contact flanges, one of said fixed contact members being provided with a transversely extending groove one of the side walls of which with the other fixed contact member provide spaced contact surfaces resiliently en gageable by the mobile contact upon movement of the stem in one direction and the other side wall of the groove constituting an abutment resiliently engageable by the mobile contact upon movement thereof in the opposite direction to disengage said contact surfaces, and actuating means including a stem axially disposed within said main chamber and operatively connected to said mobile contacts and movable to make or break a circuit through adjacent contact flanges.

11. A relay comprising an envelope including a tubular intermediate envelope portion arranged about a longitudinal axis and end walls closing opposite ends of the tubular intermediate envelope portion to define therewith an hermetically sealed main chamber, a plurality of axially spaced electrically conductive annular contact flanges arranged on the intermediate envelope portion to divide the main chamber into a pair of auxiliary contact chambers with one of said contact flanges constituting a transverse wall common to both said contact chambers, 21 contact assembly including fixed and mobile contact members within each auxiliary contact chamber, two of said fixed contact members being supported on said common contact flange with the contact surfaces thereof lying in adjacent chambers, each mobile contact member movable to make or break an electric circuit through adjacent contact flanges, and actuating means including a stem axially disposed within said main chamber and operatively connected to said mobile contacts and movable to make or break a circuit through adjacent contact flanges.

References Cited by the Examiner UNITED STATES PATENTS 2,976,382 3/61 Lee 200-144 3,017,479 1/62 Jennings 200-144 3,103,738 9/63 Chase 29-15555 3,137,061 6/64 Lalak 29--203 BERNARD A. GILHEANY, Primary Examiner. ROBERT K. SCHAEFER, Examiner. 

1. A RELAY COMPRISING AN ENVELOPE INCLUDING A TUBULAR INTERMEDIATE ENVELOPE PORTION ARRANGED ABOUT A LONGITUDINAL AXIS AND END WALLS CLOSING OPPOSITE ENDS OF THE TUBULAR INTERMEDIATE ENVELOPE PORTION TO DEFINE THEREWITH AN HERMETICALLY SEALED MAIN CHAMBER, A PLURALITY OF AXIALLY SPACED ELECTRICALLY CONDUCTIVE ANNULAR CONTACT FLANGES ARRANGED ON THE INTERMEDIATE ENVELOPE PORTION TO DIVIDE THE MAIN CHAMBER INTO A PLURALITY OF AUXILIARY CONTACT CHAMBERS, A CONTACT ASSEMBLY INCLUDING FIXED AND MOBILE CONTACT MEMBERS INSULATINGLY SUPPORTED ON THE ENVELOPE AND ENCLOSED WITHIN EACH AUXILIARY CONTACT CHAMBER, EACH MOBILE CONTACT MEMBER MOVABLE TO MAKE OR BREAK AN ELECTRIC CIRCUIT THROUGH ADJACENT CONTACT FLANGES, AND ACTUATIANG MEANS INCLUDING A STEM AXIALLY DISPOSED WITHIN SAID MAIN CHAMBER AND OPERATIVELY CONNECTED TO SAID MOBILE CONTACTS AND MOVABLE TO MAKE OR BREAK A CIRCUIT THROUGH ADJACENT CONTACT FLANGES. 